Changes in the curvature of sperm apical hooks in murine rodents

Biologia ◽  
2011 ◽  
Vol 66 (5) ◽  
Author(s):  
Martin Šandera ◽  
Petra Andrlíková ◽  
Michaela Frolíková ◽  
Pavel Stopka

AbstractSperm apical hooks in murine rodents play an important role in sperm competition. Apical hooks are more curved and longer in species with relatively larger testes, that is in species with a higher risk of sperm competition. The sperm can form aggregations, ‘trains’, that can move faster than individual sperm, thus reaching the egg earlier as was observed in Apodemus sylvaticus. The apical hook plays an important role for train formation. This study focuses on the changes in the curvature of sperm apical hooks during the final stages of spermiogenesis and stages before fertilization (sperm-life span). Apical hook curvatures of field mice (A. agrarius and A. sylvaticus) vary significantly between dormant and active sperm. In contrast, there are no significant differences among the stages in the eastern house mouse. Since there are high ranges of angle values in all stages, the mean angles of apical hook curvature are not appropriate for evaluating risk of sperm competiton. The ranges of angle values point to a level of flexibility of the apical hooks. The lengths of sperm hooks in individual species do not change during particular stages. The length and flexibility of the sperm apical hooks are important for the formation of sperm aggregations, thus these sperm characters indicate the risk of sperm competition and the sperm strategies in murine rodents.

2018 ◽  
Vol 30 (11) ◽  
pp. 1434 ◽  
Author(s):  
Tessa Pahl ◽  
Hanna J. McLennan ◽  
Yun Wang ◽  
Anang S. Achmadi ◽  
Kevin C. Rowe ◽  
...  

It is widely accepted that in mammals a causal relationship exists between postcopulatory sexual selection and relative testes mass of the species concerned, but how much it determines sperm size and shape is debatable. Here we detailed for the largest murine rodent tribe, the Rattini, the interspecific differences in relative testes mass and sperm form. We found that residual testes mass correlates with sperm head apical hook length as well as its angle, together with tail length, and that within several lineages a few species have evolved highly divergent sperm morphology with a reduced or absent apical hook and shorter tail. Although most species have a relative testes mass of 1–4%, these derived sperm traits invariably co-occur in species with much smaller relative testes mass. We therefore suggest that high levels of intermale sperm competition maintain a sperm head with a long apical hook and long tail, whereas low levels of intermale sperm competition generally result in divergent sperm heads with a short or non-existent apical hook and shorter tail. We thus conclude that sexual selection is a major selective force in driving sperm head form and tail length in this large tribe of murine rodents.


PLoS ONE ◽  
2013 ◽  
Vol 8 (7) ◽  
pp. e68427 ◽  
Author(s):  
Martin Šandera ◽  
Tomáš Albrecht ◽  
Pavel Stopka

1993 ◽  
Vol 70 (04) ◽  
pp. 676-680 ◽  
Author(s):  
H F Kotzé ◽  
V van Wyk ◽  
P N Badenhorst ◽  
A du P Heyns ◽  
J P Roodt ◽  
...  

SummaryPlatelets were isolated from blood of baboons and treated with neuraminidase to remove platelet membrane sialic acid, a process which artificially ages the platelets. The platelets were then labelled with 111In and their mean life span, in vivo distribution and sites of Sequestration were measured. The effect of removal of sialic acid on the attachment of immunoglobulin to platelets were investigated and related to the Sequestration of the platelets by the spleen, liver, and bone marrow. Removal of sialic acid by neuraminidase did not affect the aggregation of platelets by agonists in vitro, nor their sites of Sequestration. The removal of 0.51 (median, range 0.01 to 2.10) nmol sialic acid/108 platelets shortened their life span by 75 h (median, range 0 to 132) h (n = 19, p <0.001), and there was an exponential correlation between the shortening of the mean platelet life span and the amount of sialic acid removed. The increase in platelet-associated IgG was 0.112 (median, range 0.007 to 0.309) fg/platelet (n = 25, p <0.001) after 0.79 (median, range 0.00 to 6.70) nmol sialic acid/108 platelets was removed (p <0.001). There was an exponential correlation between the shortening of mean platelet life span after the removal of sialic acid and the increase in platelet-associated IgG. The results suggest that platelet membrane sialic acid influences ageing of circulating platelets, and that the loss of sialic acid may have exposed a senescent cell antigen that binds IgG on the platelet membrane. The antibody-antigen complex may then provide a signal to the macrophages that the platelet is old, and can be phagocytosed and destroyed.


2021 ◽  
pp. 039139882110322
Author(s):  
Frédéric J Baud ◽  
Vanessa Seif ◽  
Pascal Houzé ◽  
Jean-Herlé Raphalen ◽  
Benoît Pilmis ◽  
...  

Introduction: Adsorption of gentamicin in a polyacrylonitrile filter was previously evidenced in a session lasting 6 h using the NeckEpur model. We extended the study over three consecutive days to mimic the 72-h life span of a filter. Methods: Prismaflex® monitor and ST150® filter were used in the continuous diafiltration (CDF) mode at a 2.5 L/h flowrate. The daily session started with a 6-h session of CDF. Thereafter, the 5-L central compartment was changed using a bag free of gentamicin to assess gentamicin release over the following 18 h. Experiments were repeated on Day 2 and stopped at the end of the 6-h session of CDF on Day 3. The experiment was performed in duplicate. Results: At a 2.5 L/h diafiltration flowrate, the mean daily clearances of gentamicin were 5.5, 4.0, and 3.3 L/h, respectively. The mean diafiltration and adsorption ratios in the daily elimination of gentamicin were 32/68%, 58/42%, and 88/12%, respectively. During days 1 and 2, the mean amount of gentamicin released from the ST150® filter were 14 and 34 mg, respectively. Conclusion: The pharmacokinetics of gentamicin over 3 days is strongly altered by adsorption in the same filter with a progressive decrease of elimination by adsorption, suggesting saturation of the filter. One limitation of our study results from the mode of administration using a bolus dose instead of an infusion over 30 min. Adsorption adds a clearance to those of diafiltration. The time-dependency of gentamicin clearance precludes using a constant dosage regimen over the filter’s life span.


Blood ◽  
1987 ◽  
Vol 70 (3) ◽  
pp. 652-656
Author(s):  
V Castle ◽  
G Coates ◽  
JG Kelton ◽  
M Andrew

Thrombocytopenia is a common occurrence (20%) in sick neonates, but the causes have not been well studied. In this report we demonstrate that thrombocytopenia in the neonate is characterized by increased platelet destruction as shown by shortened homologous 111In-oxine-labeled platelet life spans. Thirty-one prospectively studied thrombocytopenic neonates were investigated by measuring the 111In-labeled platelet life span, platelet-associated IgG (PAIgG), and coagulation screening tests. In every infant, the thrombocytopenia was shown to have a destructive component since the mean platelet life span was significantly shortened to 65 +/- 6 (mean +/- SEM) hours with a range of one to 128 hours compared with adult values (212 +/- 8; range, 140 to 260; gamma function analysis). The platelet survival was directly related to the lowest platelet count and inversely related to both the highest mean platelet volume and duration of the thrombocytopenia. In 22 infants the percent recovery of the radiolabeled platelets was less than 50%, which suggested that increased sequestration also contributed to the thrombocytopenia. Infants with laboratory evidence of disseminated intravascular coagulation (n = 8) or immune platelet destruction evidenced by elevated levels of PAIgG (n = 13) had even shorter platelet survivals and a more severe thrombocytopenia compared with the ten infants in whom an underlying cause for the thrombocytopenia was not apparent. Full-body scintigraphic images obtained in 11 infants showed an increased uptake in the spleen and liver, with a spleen-to- liver ratio of 3:1. This study indicates that thrombocytopenia in sick neonates is primarily destructive, with a subgroup having evidence of increased platelet sequestration.


1995 ◽  
Vol 18 (1) ◽  
pp. 1
Author(s):  
R.T. Gemmell

The brushtail possum is a common arboreal marsupial that is well adapted to the Australian urban environment and to rearing in captivity. Data obtained from 100 female possums housed in a semi-captive colony over a 7 year period demonstrate the reproductive capability of this marsupial. The main breeding season is from March to June with a declining number of births occurring from July to October. The possums gave birth to 259 single young and one set of twins. The range of the lactation period was from 177 to 200 days with the birth of the subsequent young occurring at 188.4 ± 4.1 days post partum (SD, n = 5). The growth rate of the young female possum varied greatly after day 100 post partum, the mean body weight of possums at day 172, being 753.0 ± 76.2g (SD, n = 5) with a range of 685 to 851 g. Female possums, with a mean body weight of 2171 ± 388g, gave birth to their first litter on day 345.9 ± 69.3 days postpartum (mean, SD, n = 7). Although two female possums trapped in the wild were held in captivity for 64 and 63.4 months and one possum bred in captivity had a life span of 51.5 months, the mean life span was 21.0 ± 12.5 months (SD, n =3D 8), with a range of 14.3 to 51.5 months. This life span is very variable and it is of interest to determine if this is an artefact of captivity or is also observed in the wild.


1975 ◽  
Author(s):  
A.-L. Bergström ◽  
J. Kutti

In 16 patients (3 males and 13 females) with SLE platelet survival and platelet production were determined. At the time of study 3 patients received no therapy, 10 were treated with corticosteroids, and the remaining 3 received corticosteroids and azathioprin. The control group consists of 21 healthy male volunteers. In all experiments autologous platelets labelled with 51Cr were employed.The mean peripheral platelet count for the SLE patients was 222,000/μl, range 122,000-347,000/μl. In this group the mean for platelet mean life span (MLS) was 6.8±0,3 (S. E.), range 5.5-9.7 days, and did not differ from the mean for the controls (6.9±0.3 days). In the SLE group the mean platelet turnover was 49,000 ±8,000/μl/day. The corresponding value for the controls was 43,000 ± 3,000/μl/day. The values for platelet MLS and platelet turnover in SLE patients were not related to given therapy.Previously it has been suggested that a state of compensated thrombocytolysis is present i SLE. Our results could, however, not confirm this.


Blood ◽  
1986 ◽  
Vol 67 (2) ◽  
pp. 544-546 ◽  
Author(s):  
LJ Benjamin ◽  
JM Manning

Abstract Glyceraldehyde has been demonstrated to be an antisickling agent in vitro. In the present investigation, chromium-51 red cell studies were used to investigate the life span in vivo of sickle erythrocytes after treatment with glyceraldehyde in vitro. The mean survival (T1/2) of control cells was 5.8 +/- 1.6 days, whereas cells treated with 10 mmol/L or 20 mmol/L glyceraldehyde survived 9.0 +/- 1.4 (P less than .05) and 11.3 +/- 0.8 (P less than .002) days, respectively. The extent of modification by glyceraldehyde was 0.4 to 1.0 lysine residue per hemoglobin tetramer. These studies demonstrate not only a prolongation of the life span of sickle erythrocytes by treatment with glyceraldehyde but also the absence of any deleterious effects that would be revealed by this study.


2010 ◽  
Vol 79 (9) ◽  
pp. S3-S8 ◽  
Author(s):  
Eva Straková ◽  
Pavel Suchý ◽  
Romana Kábelová ◽  
František Vitula ◽  
Ivan Herzig

The present paper extends the knowledge of selected blood indicators in six species of feathered game such as helmeted guineafowl (Numida meleagris), common pheasant (Phasianus colchicus), Japanese quail (Coturnix coturnix japonica), chukar (Alectoris chucar), grey partridge (Perdix perdix) and wild turkey (Meleagris gallopavo), reared in the Czech Republic and Europe. The red blood cell (RBC) values in individual species of feathered game ranged as follows: the mean RBC counts varied in a range of 2.10 - 2.58 T/l; haematocrit values were in a range of 0.33 - 0.39 1/1; haemoglobin concentration varied in a range of 101.20 - 129.13 g/l; mean corpuscular haemoglobin concentration (MCHC) ranged from 28.63 to 35.44%; mean corpuscular haemoglobin (MCH) varied in a range of 46.15 - 62.07 pg and the mean corpuscular volume (MCV) was 147.66 - 178.20 fl. Except for the total concentration of haemoglobin and the mean corpuscular haemoglobin concentration, no significant differences were found between the mean values of RBC values in individual species of feathered game. However, some differences between species were found in white blood cell (WBC) values, ranging as follows: the total WBC count ranged from 13.55 to 26.90 G/l, basophil granulocytes from 0.011 to 0.110 G/l, eosinophil granulocytes from 0.011 to 0.593 G/l, neutrophil granulocytes from 1.868 to 6.661 G/l, lymphocytes from 10.937 to 20.922 G/l and monocytes from 0.034 to 0.199 G/l. Most values showed significant (P ⪬ 0.05) to highly significant (P ⪬ 0.01) interspecies differences. The main goal of the study was to investigate selected haematological indicators in six major species of feathered game.


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